Caracterização térmica e mecânica de materiais impressos pelo processo de estereolitografia

Abstract

Additive Manufacturing (AM) consists of a manufacturing process based on the addition of material in successive layers, in which it is possible to generate 3D physical parts obtained directly from CAD (Computer Aided Design) modeling files. It is used in several areas such as automobile industry, engineering, architecture and in the last decades has been applied in the area of health technology, involving the production of orthoses and prostheses for treatment / rehabilitation of patients. In order to better understand the processes and behaviors of the materials used some research has been developed. In this sense, the present research aimed to characterize thermally and mechanically the performance of the Sheraprint-sg resin (used for making surgical guides) printed by the Stereolithography method (SLA). The applied methodology tried to characterize the samples made in two orientations in the printing tray (group 1 / vertical - x axis and group 2 / horizontal - y axis) and the rate with internal fill rates of 50% and 100% through the Differential Scanning Calorimetry (DSC), Thermogravimetry (TGA) Dynamic-Mechanical Analysis (DMA) and Vickers Microhardness. From the analysis of the DSC / TGA curves, it was possible to calculate the enthalpy (5,677 J / g and 1.0988 J / g) and the degradation temperature (396 ° C) of the Sheraprint-sg resin. For the DMA test the results showed statistically significant differences (p <0.05) according to the groups evaluated considering the values of Tg (E ') and Tg (Tan Delta) (p <0.001). In the first parameter evaluated, the highest value was observed in the samples of the x - 50% (59.10 ° C), y - 50% (57.73 ° C) and x - 100% (57.47 °) W). For the second parameter evaluated, the highest values were observed in the samples of the x - 50% (127.67 ° C) and the y - 50% (128.83 ° C) axis groups. Regarding the modulus of elasticity, the samples of the x - 100% axis group (2155.33MPa at 30 ° C and 272.67MPa at 100 ° C) showed marked stiffness, showing better performances and greater maximum force for the material. Regarding microhardness, the materials printed on the x - 100% axis (21.84HV) obtained higher resistance to deformation. In this way, the influence of fill rate and orientation position was observed for materials made three- dimensional, therefore, the characteristics most favorable to the use in additive manufacture for health will depend on its applicability.